what color LED would u consider be a close match to a turn signal amber?

yellow?
orange?
red-orange?

TIA

Amber.

Yellow or orange is a different wave length and will look very unprofessional in turn signal application. The best single LEDS I have found so far is the Superflux Luxeon LED. It is 3-5 times brighter than a regular 5mm diameter LED, which makes it excellent. There are brigther LEDs, but they will be too bright and look "spotty" on lens. If you feel electrically challenged, an amber flexible LED array may be the right choice for u.